力大,固定桥连接体薄弱可导致()
A.松动、脱落
B.变色
C.穿孔、破裂
D.磨损
E.折断
参考答案:E
The students should ________ to choose their own clothes. It will be a good way _____ themselves happy.
A.allow, to keep
B.allowed, keeping
C.be allow, keeping
D.be allowed, to keep
B类火灾是指()引起的火灾。
A、可燃固体
B、可燃液体
C、可燃气体
D、核物质